Washer mechanism for electrostatic precipitator

ABSTRACT

An upright panel of at least one precipitator cell with a plurality of substantially vertical disposed plates is provided with a washer header assembly supported for traversing movement in front of the panel and a rotatable sprocket is journalled on said header assembly with its teeth engaging a sprocket chain supported in front of the panel along the path of the traversing movement of the header assembly so that the header assembly will traverse the panel as the sprocket is rotated.

United States Patent Burney Dec. 5, 1972 154] WASHER MECHANISM FOR ELECTROSTATIC PRECIPITATOR [72] Inventor: Ivan T. Burney, Pittsburgh, Pa.

[73] Assignee: Westinghouse Electric Corporation, Pittsburgh, Pa.

[22] Filed: May 27, 1970 [21] Appl. No.: 40,794

[52] US. Cl. ..55/118, 55/120, 74/31 Primary Examiner-Dennis E. Talbert, Jr. Attorney-F. H. Henson and F. E. Blake 7] ABSTRACT An upright panel of at least one precipitator cell with a plurality of substantially vertical disposed plates is provided with a washer header assembly supported for traversing movement in front of the panel and a rotatable sprocket is joumalled on said header assembly with its teeth engaging a sprocket chain supported in front of the panel along the path of the traversing movement of the header assembly so that the header assembly will traverse the panel as the sprocket is rotated.

6 Claims, 5 Drawing Figures [51 I Int. Cl ..B03C 3/78 [58] Field 01 Search ..55/1 18, 120; 74/29, 30, 31, 74/422, 37

[56] References Cited UNITED STATES PATENTS 129,226 7/1872 Hincke ..74/31 X 348,162 8/1886 Huber et a1 ..74/31 X 466,352 1/1892 Lewis ..74/30 654,446 7/ 1 900 Durel ..74/30 788,226 4/1905 Sweet ..74/31 X 1,191,695 7/1916 I-Iartley ...74/31 1,299,803 4/1919 Smith ..74/422 X 1,895,618 1/1933 Fedeler ..55/242 X 2,244,607 6/ 1941 Blakely ..74/ 3 1 2,591,404 4/1952 Carlson .'.55/ l 18 MTENTED DEC 5 3,704,571

sum 2 OF 3 FIG.2

SHEET 3 [IF 3 FIG.4

PATENTED DEC 5 2 WASHER MECHANISM FOR ELECTROSTATIC PRECIPITATOR CROSS REFERENCE TO RELATED APPLICATIONS So far as is known, this invention is not related to any co-pending patent applications.

BACKGROUND OF THE INVENTION Electric precipitators are widely used to remove dirt and pollutants from atmospheric gases and it has been a common practice to position one or more precipitator cells in an upright panel in a manner that they may be washed to remove accumulated deposits on the precipitator plates at predetermined time intervals. There are many forms of washing apparatus for this purpose and a common form is a vertically disposed header tube assembly having a plurality of spray nozzles in an arrangement that may be traversed in front of a precipitator panel so that all parts of the precipitator plates may be contacted with washing-fluids or the like. In order that the washing mechanism'can be reliably operated by remote control without frequent maintenance, it should be simply constructed to have a minimum of moving and wearing parts requiring lubrication, and maintenance.

PRIOR ART Examples of prior patents showing electrical precipitators with washing apparatus are as follows:

2,591,404 Carlson 2,6l5,529 Lincoln October 28, 1952 2,737,257 Warburton March 6, 1956 Applicant is not aware of any prior patents disclosing the simplified form of washing apparatus for electrical precipitators as described and claimed by this patent application.

SUMMARY OF THE INVENTIONS According to the invention, one or more precipitator cells are arranged in a generally upright panel with their parallel plate electrodes extending substantially vertically. A substantially vertically disposed washer header or tube is suspended from a header assembly that is movably mounted on a track extending in front of and across the panel near the upper portions thereof. The lower end of the tube may be provided with an additional guide means engaging a track surface extending along the lower portions of the panel to maintain a desired attitude for the header assembly as it traverses the panel for washing purposes. A flexible sprocket chain is supported in front of the panel along the path of movement of the header assembly and a rotatable shaft with a sprocket gear having its teeth engaging the chain sprockets is journaled on the header assembly so that rotation of the shaft and sprocket will vause the header assembly to move along the chain and traverse the front of the panel for washing purposes. In the preferred form of the invention, the shaft is rotated by an electric motor in one direction of rotation only and there are means disposed at each end of the chain to move the sprocket around the end of the chain from engagement with one side of the chain into engagement with the other side of the chain so that the header assembly will be reciprocally traversed as the sprocket is continuously rotated in one direction of rotation.

April 1, 1952 Various other features and advantages of the invention will be apparent with reference to the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of a panel of precipitator cells with a washer header assembly disposed at an approximately intermediate position in front of the panel.

FIG. 2 is a side elevational view of the apparatus as shown by FIG. 1.

FIG. 3 is an enlarged fragmentary view showing the header apparatus in a position to be moved from the left-hand end of the flexible chain.

FIG. 4 is a side elevational view similar to that of FIG. 3, and

FIG. 5 is a fragmentary detail view showing the sprocket and chain at intermediate positions around the end of the flexible chain as moving from engagement with the underside of the chain into engagement with the upper side of the chain for traversing movement from left to right of the panel.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIGS. 1 and 2 of the drawings, a plurality of the precipitator cell units are shown at 10 through 18 to be arranged in panel form within the substantially vertical frame member uprights 19 and 20. Each of the precipitator cells 10-18 may be of any known design and includs a plurality of substantially vertically disposed parallel plate electrodes upon which pollutants in the gases passing through the panel are deposited during operation of the precipitator apparatus as is well known to those skilled in the art. Because of the accumulation of deposits on the electrode assemblies of the precipitator cells 10-18, it is necessary to periodically wash the deposits off of the electrodes in order to maintain the efficiency of the precipitator apparatus.

A washer header tube 25 is suspended from a header assembly 26 that is movably mounted to depend from the track 27 extending generally across the front of the panel near the upper portions thereof. Although the header assembly 26 may be supported on the track 27 in any suitable manner, a pair of wheels 28 and 29 are shown to enable the header assembly 26 to be easily movable along the track 27 in either direction. If desired, the lower end of the washer tube 25 may be provided with a bracket member 31 having a wheel 32 engaging a lower track surface 33 of the precipitator panel 3. Thus, the washer tube 25 is maintained in a desired substantially vertical attitude as it may be moved to traverse in front of the precipitator panel. It should be understood that this invention is not limited to any particular arrangement for movably supporting the depending washer tube 25 on the track surface in front of the precipitator panel, and for example the lower bracket 31 can be omitted without substantially impairing'the operation of the washer tube traversing mechanism being described.

As more clearly shown by FIGS. 1, 3, 4, and 5 of the drawings, a flexible sprocket chain 40 is suspended along the path of movement of the header assembly 26 in front of the precipitator panel. A rotatable shaft 41 is journaled on the header assembly bracket 26 and a OlOl toothed sprocket gear 42 is mounted on the shaft 41 for rotation therewith. As the shaft 41 and sprocket gear 42 are rotated in a clockwise direction, with the teeth of the sprocket gear 42 engaging the upper side of the sprocket chain 40 as shown by FIG. 3 of the drawings, the bracket assembly 26 will be moved in a direction to the right of the drawing for traversing the precipitator panel from left to right. In the preferred form of the invention, the sprocket gear 41 is rotated by means of an electric motor 43 also mounted on the header bracket assembly 26. It should be obvious that the shaft 41 and sprocket 42 maybe rotated by any suitable mechanism other than the electric motor and may be rotated in either direction of rotation for moving the header assembly accordingly. I

As most clearly shown by FIGS. 3 and 5 of the drawings, however, the preferred form of the invention provides that the electric motor 43 be simply constructed and energized for rotation in one direction of rotation only. For purposes of this description, it will be assumed that the shaft 41 and sprocket 42 are rotated in a clockwise direction. While the teeth of the sprocket 42 are engaging the upper side of the sprocket chain 40 as shown by FIG. 3 of the drawings, the clockwise rotation of the sprocket 42 will cause the header assembly to move from left to right as previously described. Each end of the flexible chain 40 is supported on a pivotal bracket or link member 50 and 51. The link members 50 and 51 are substantially identical except that link 50 is. positioned with its groove 52 curving around the right end 43 of the flexible chain 40 and .the link 51 is positioned with its groove'54 curving around the left end 44 of the flexible chain 40. When the bracket assembly 26 approaches the right end of the panel assembly continued rotation of the sprocket gear 42 and the shaft end 41 causes the Referring again to FIG. 4 of the drawings, in the preferred form of the invention, a generally U-shaped member 60 is positioned coaxially of the shaft 41 with its arms 61 and 62 extending above and below the sprocket 42 so as to maintain the engagement of the sprocket teeth and chain as'the sprocket is rotated to move along the chain.

sprocket and shaft to be rotated around the end 43 of the flexible chain with the shaft 41 engaged in the groove 52 of the link member 50. A continued clockwise rotation of the shaft 41 and sprocket therefor brings the sprocket teeth into an engagement with the underside of the flexible chain 40, thus, causing the header assembly 26 to move from right to left as the sprocket gear 42 continues torotate in a clockwise direction. When the header assembly 26 approaches the left end 44 of the chain 40, the shaft 41 and sprocket 42 are moved around that end of the chain as shown by FIG. 5 of the drawings with the shaft end 41 engaged in the link groove 54. Thus, the sprocket teeth 42 are again brought into engagement with the upper side of the flexible chain 40 so that continued clockwise rotation of the shaft 41 and sprocket 42 will cause the header assembly 26 to again reverse direction and move to traverse the panel from left to right. In such manner continuous rotation of the shaft 41 and sprocket 42 in a clockwise direction will cause the header assembly 26 to reciprocate back and forth in a traversing movement in front of the precipitator panel. At the end of the washing operation which may be timed or controlled for a predetermined number of traversing movements, a switching control circuit (not shown) will provide for deenergization of the electric motor 43 so as to discontinue the traversing movement of the washer tube.

There has been described above an extremely simple and reliable traversing mechanism for moving the washer tube assembly in a traversing movement across the panel and precipitator cells. It will be noted that only one rotating shaft and sprocket is required for the entire traversing apparatus with the exception of the supporting wheels and, of course, the supporting wheels may be replaced by a sliding support if desired. Various modifications will occur to those skilled in the art. For example, instead of a flexible sprocket chain, a flexible rack member having stamped perforations for reversing the sprocket teeth could be used. Also a substantially rigid rack member could be used in place of the chain.

I claim:

1. An electrostatic precipitator comprising, an upright panel of at least one precipitator cell, each cell having a plurality of substantially vertically disposed plate electrode elements upon which dirt particles are to be precipitated, a substantially horizontal track extending in front of the upper portions of said panel, a washer header assembly supported to depend from said track for traversing movement in front of said panel for directing a washing fluid on said elements as said header is traversed, a sprocket chain supported adjacent said track in front of said panel along the path of movement of said header assembly, a bracket extending from a lower portion of said header assembly into sliding engagement with a lower front surface of said panel responsive to gravitational forces'to maintain a desired essentially vertical attitude of said header during traversing movement, and a shaft rotatably mounted on said header assembly and having a sprocket gear secured thereto in a manner to engage its teeth with the sprockets of said chain whereby said header assembly is traversed in front of said panel when said shaft is rotated. 1

2. The invention of claim 1 in which said shaft is rotated by an electric motor carried on said header assembly.

3. The invention of claim 2 in which there is means at each end of said chain for guiding said sprocket around the end of the chain from engagement with one side of the chain to engagement with the other side of the chain whereby said header assembly is reciprocally traversed as said shaft is continued to be rotated in a single direction of rotation.

4. The invention of claim 1 in which there is means at each end of said chain for guiding said sprocket around the end of the chain from engagement with one side of the chain to engagement with the other side of the chain whereby said header assembly is reciprocally traversed as said shaft is continued to be rotated ina single direction of rotation.

5. The invention of claim 4 in which there is means carried by said header assembly to extend above and below said sprocket in a manner to maintain said sprocket in engagement with the chain during either direction of traversing movement of the header assembly.

6. The invention of claim 1 in which there is means carried by said header assembly to maintain said chain in engagement with said sprocket. 5 

1. An electrostatic precipitator comprising, an upright panel of at least one precipitator cell, each cell having a plurality of substantially vertically disposed plate electrode elements upon which dirt particles are to be precipitated, a substantially horizontal track extending in front of the upper portions of said panel, a washer header assembly supported to depend from said track for traversing movement in front of said panel for directing a washing fluid on said elements as said header is traversed, a sprocket chain supported adjacent said track in front of said panel along the path of movement of said header assembly, a bracket extending from a lower portion of said header assembly into sliding engagement with a lower front surface of said panel responsive to gravitational forces to maintain a desired essentially vertical attitude of said header during traversing movement, and a shaft rotatably mounted on said header assembly and having a sprocket gear secured thereto in a manner to engage its teeth with the sprockets of said chain whereby said header assembly is traversed in front of said panel when said shaft is rotated.
 2. The invention of claim 1 in which said shaft is rotated by an electric motor carried on said header assembly.
 3. The invention of claim 2 in which there is means at each end of said chain for guiding said sprocket around the end of the chain from engagement with one side of the chain to engagement with the other side of the chain whereby said header assembly is reciprocally traversed as said shaft is continued to be rotated in a single direction of rotation.
 4. The invention of claim 1 in which there is means at each end of said chain for guiding said sprocket around the end of the chain from engagement with one side of the chain to engagement with the other side of the chain whereby said header assembly is reciprocally traversed as said shaft is continued to be rotated in a single direction of rotation.
 5. The invention of claim 4 in which there is means carried by said header assembly to extend above and below said sprocket in a manner to maintain said sprocket in engagement with the chain during either direction of traversing movement of the header assembly.
 6. The invention of claim 1 in which there is means carried by said header assembly to maintain said chain in engagement with said sprocket. 